title: Experimental correction of irregular corneal astigmatism using topography-based flying-spot-mode excimer laser photoablation.
abstract: OBJECTIVE
  To present a novel experimental approach for treating irregular corneal astigmatism.
  
  
  METHODS
  After decomposition of topographic analysis data into orthogonal Zernike polynomials, a regular target surface was defined, and the ablation profile was calculated. In a polymethylmethacrylate with an irregular surface, computer-controlled ablation was performed using a 193-nm excimer laser in "flying-spot mode."
  
  
  RESULTS
  The difference between flattest and steepest hemimeridians in the 3-mm zone, surface regularity index, and surface asymmetry index were reduced from 8.7 to 1.1 diopters, 1.19 to 0.39, and 1.84 to 0.14, respectively.
  
  
  CONCLUSIONS
  Tying corneal topography into laser software offers a straightforward concept for correction of irregular corneal astigmatism in an experimental model.
authors.affiliation: Department of Ophthalmology, University of Erlangen-Nürnberg, Germany. berthold.seitz@augen.med.uni-erlangen.de
authors.forename: B
authors.initials: B
authors.lastname: Seitz
authors.forename: A
authors.initials: A
authors.lastname: Langenbucher
authors.forename: M M
authors.initials: MM
authors.lastname: Kus
authors.forename: M
authors.initials: M
authors.lastname: Harrer
mesh_terms: D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D054018:Lasers, Excimer; D008953:Models, Anatomic; D018903:Photorefractive Keratectomy / Q000379:methods*; D019904:Polymethyl Methacrylate
chemical_list: D019904:Polymethyl Methacrylate